What are enzymes? What is the importance of enzymes for living beings?

Enzymes are proteins that are catalysts of chemical reactions. Chemistry shows us that catalysts are non-consumable substances that reduce the activation energy necessary for a chemical reaction to occur. Enzymes are highly specific to the reactions they catalyze. They are of vital importance for life because most of the chemical reactions in cells and tissues are catalyzed by enzymes. Without enzyme action, those reactions would not occur or would not happen with the required speed for the biological processes in which they are involved.